Aphid-Resistant Soybeans Vital to Farmer Profitability

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Aphid management is vital to the success of Ohio’s soybean crop, and several programs to fight aphids are being made possible with funding from the USDA, Ohio State University’s (OSU) Ohio Agricultural Research and Development Center (OARDC) and the Ohio Soybean Council (OSC) and soybean checkoff.

Also known as plant lice, aphids rapidly reproduce and live on sap from host plants. These insects deform or kill plants and invite other worrisome insects to infected cropland because of their honeydew secretions. Aphids can also be infected with fungi, viruses and bacteria to further damage crops, and have the potential to greatly impact Ohio’s 26,000 soybean farmers and their multifaceted industry valued at $1.9 billion.

Researchers are currently developing a new soybean variety that contains aphid-resistant genes. Designed to both deter aphids while specifically addressing Ohio’s climate, this new variety is financially promising for Ohio’s soybean farmers. Ohio experienced an increased number of aphids among its soybean fields this season, which dampens the financial prospects of farmers and impacts the success of other agricultural sectors in the state.

“Resistant soybean varieties are necessary to keep our farmers profitable,” says John Lumpe, OSC executive director. “We’re proud to contribute to research efforts that are securing the success of our state’s farmers.”

OSC funding has also permitted OSU scientists to determine genetic markers to track aphid migration within and into Ohio. Researchers scouted Ohio farmland in August to assess pest damage and to collect aphid samples for further testing. Understanding aphid traffic patterns will assist researchers in formulating resistant varieties.

Ohio is involved in additional research efforts also funded by soybean checkoff investments directed by the North Central Soybean Research Program (NCSRP), an organization comprised of state soybean checkoff boards in Ohio and 11 other states. NCSRP works to coordinate soybean production research efforts on a regional level, and the organization’s aphid research aims to create soybean varieties that can tolerate larger populations of soybean aphids, while simultaneously slowing aphid development.

Aphids first appeared in Ohio in 2001, and buckthorn, a common shrub found throughout the state, serves as the pests’ overwintering host. Higher populations of aphids on soybeans normally occur every other year, creating a two-year cycle of high and low populations. But according to Dr. Ron Hammond, an entomologist with OSU Extension and OARDC, this two-year cycle might be changing.

“The movement, or flights, of aphids onto buckthorn occurred much later than expected this year, more into mid- to late August,” says Hammond. “These flights lasted well into September, and resulted in extremely large populations of aphids on buckthorn, which is unusual during an outbreak year.”

Due to the high population of aphids on buckthorn, researchers also expected to find a large number of eggs. But that wasn’t the case. It appears that a fungal pathogen infected the aphid population causing significant mortality.

What does this mean for farmers in 2010?

“At this time, we have to admit we do not know,” says Hammond. “We will recommend that farmers maintain extra vigilance next summer until we see trends in what the soybean aphid population is doing. Whether the aphid remains in a two-year cycle with 2010 having low populations, or whether we lose the two-year cycle and have a large outbreak next year, remains to be seen.”

Researchers will continue to monitor aphid populations and keep farmers informed. And thanks to another project with OSC and the soybean checkoff, researchers are working to map the buckthorn in Ohio, so that aphid populations can be tracked more accurately.